Composable Rust Testing

@jonathanbelolo/composable-rust-composable-rust-testing

Expert knowledge for testing Composable Rust applications. Use when writing unit tests for reducers, setting up integration tests with real dependencies, using test utilities (TestStore, FixedClock, mocks), working with testcontainers for PostgreSQL/Redpanda, property-based testing, or questions about testing patterns and best practices.